WARNING: Oracle executable binary mismatch detected.

Issue:
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 Binary of new process does not match binary which started instance
issue alter system set "_disable_image_check" = true to disable these messages
Mon May 13 14:25:57 2019
WARNING: Oracle executable binary mismatch detected.
 Binary of new process does not match binary which started instance
issue alter system set "_disable_image_check" = true to disable these messages

Solution:
=========
Whenever the binary is linked or changed, you need to make sure that all instances are shutdown.
So in this case, the following action plan would fix this problem:

Shutdown the instance(Database and Applications)
Ensure that all related processes have been killed
Restart the instance (Database and Applications)